Degradation Analysis and Replacement Planning

16 April 2018

National Grid has more data than ever before on the condition of their Overhead Line assets and their operating environment. They monitor asset condition using advanced techniques, such as helicopter inspections with a High Definition Camera, and have enhanced their database capacity to store condition assessments on a component-by-component level. This paints a more granular and accurate picture of their asset portfolio, and enables innovative, condition-based asset and investment strategies.

Strategic Consulting and Technology is working with National Grid’s Electricity Transmission Asset Management team to integrate and analyse a variety of data sources and up-to-date condition information, with the aim of updating:

The Asset Health Index scoring method, which is used to determine asset replacement priorities;
The in-house asset degradation models, used for long-term forecasting;
The scope of fittings replacement strategies.
Savings in the range of £60 million are achievable through potential asset life extensions and adjusted replacement scheme scopes. Additionally, the project will enable decision-makers to optimise their asset management strategy based on a balance of risk, cost, and process complications. Finally, the project will help National Grid formulate an evidence-based justification for their performance under the previous regulatory framework.

Amey SC degradation model output. Cumulative probability of defect for spacers, by age and operating environment. 95% credible interval (HPD = Highest Posterior Density) represented as shaded bands.